GroupDIY

Project Specific Discussions => Dynamic Processors => Topic started by: Studio Mollan on November 21, 2018, 09:07:55 AM

Title: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on November 21, 2018, 09:07:55 AM
Hi,
Can anyone point me in the right direction for adding variable release and attack for this limiter. I have a hunch C1 and R4 has something to do with it.

larger value capacitor = slower release ?
thanks
/
Emil
Title: Re: DISA Vari-mu, add variable release/attack
Post by: scott2000 on November 21, 2018, 09:39:11 AM
Kingston's M670 has a nice example???

https://groupdiy.com/index.php?topic=51478.0
Title: Re: DISA Vari-mu, add variable release/attack
Post by: EmRR on November 21, 2018, 09:43:53 AM
C1/R4 is release.  Attack is fixed at 'fastest possible', as dictated by other circuit constraints.  Insert series resistance before C1/R4 to slow it. 

These things are highly interactive, if you do it as simple adjustable resistances, changing one affects the other.  Some units change the C and the R to keep adjustments more separate. 
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on November 21, 2018, 09:58:58 AM
Thanks guys.
Ok so C1/R4 are release. You know what, I'll leve it as it is. don't fix it if it aint broken right.
Title: Re: DISA Vari-mu, add variable release/attack
Post by: EmRR on November 21, 2018, 11:48:27 AM
I should say they are ’primarily’ release, there is still the charge time of the cap which is part of the attack.  At any rate it’s meant to be as fast as possible. 
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on February 02, 2019, 06:45:13 AM
Ok I am going to investigate this further. After having used it for a couple of weeks i feel i would want the option of altering the envelope. Especially the attack.

Any help is greatly appreciated. Preferably i would like to have two potentiometers for attack and release with a switch to flip between the pots and original time constants.
Help!


I should say they are ’primarily’ release, there is still the charge time of the cap which is part of the attack.  At any rate it’s meant to be as fast as possible.
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on February 02, 2019, 06:57:50 AM
How about adding a series pot before C1/R4 for a variable release, as you said, and add a switch witch a couple alternative values for C1. Say 1u5, 2u2 and 4u7? A pot for the attack would be better but i don't know how that would be done.

Ok I am going to investigate this further. After having used it for a couple of weeks i feel i would want the option of altering the envelope. Especially the attack.

Any help is greatly appreciated. Preferably i would like to have two potentiometers for attack and release with a switch to flip between the pots and original time constants.
Help!
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on February 02, 2019, 02:09:40 PM
Could this work?
Title: Re: DISA Vari-mu, add variable release/attack
Post by: EmRR on February 02, 2019, 02:35:53 PM
That's the basic idea. 
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on February 02, 2019, 08:31:12 PM
Ok cool. thanks I'll start experimenting.

That's the basic idea.
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on February 03, 2019, 03:19:36 PM
I just installed it and it works PERFECT! Thanks for your help!

That's the basic idea.
Title: Re: DISA Vari-mu, add variable release/attack
Post by: Studio Mollan on February 03, 2019, 08:10:39 PM
Pic